@font-size-base:12px;
@font-size-big:@font-size-base*(14/12);//14px
@font-size-bigger:@font-size-base*(16/12);//16px
@font-size-large:@font-size-base*(18/12);//18px
@font-size-larger:@font-size-base*(20/12);//20px
@font-size-small:@font-size-base*(10/12);//10px

@font-size-plus2:@font-size-base+2;//14px
@font-size-plus4:@font-size-base+4;//16px
@font-size-plus6:@font-size-base+6;//18px
@font-size-plus8:@font-size-base+8;//20px
@font-size-minus2:@font-size-base(-2);//10px